Electrification forces fresh perspectives on vehicle NVH

The quietness of EVs is, for many, a compelling selling point. But vehicles becoming inherently quieter overall hasn't translated into making the job of noise abatement any easier - the job's just different, asserted several NVH engineering experts at the Autotech conference in Detroit in early June. These NVH experts underlined a primary point of what's now understood about the “new” quietness of EVs: the drastic reduction of powertrain-related noise, vibration and harshness (NVH) largely means vehicle occupants now can hear and feel other NVH sources.

“A little squeak becomes more prominent” in EVs, said Jian Pan, senior director of engineering at Auria Solutions. And although this seems self-evident, Pan added that EVs can open up new or unfamiliar frequencies to occupants - and some of those frequencies can be particularly displeasing. Certain frequencies emanating from EV drive motors, for one, can be distinctly annoying, Pan said, and are quite different from the “noise signatures” of combustion engines. Meanwhile, those relatively minor squeaks and squeals coming from seat-adjustment motors and power windows, in the absence of “masking” noise from an IC powertrain, now are prominent noise sources, he added.